The Commodore 1701 and 1702 were color monitors for the C64 which accepted as input either composite video or separate
chrominance and
luminance signals, similar to the
S-Video standard, for superior performance with the C64 (or other devices capable of outputting a separated signal). Other monitors available included the 1802 and 1902. Introduced in 1986, the 1802 featured separate chroma and luma signals, as well as a composite green screen mode suitable for the C-128's 80 column screen. The 1902 had a true
RGBI 80-column mode compatible with
IBM PCs. Early in the Commodore 64's life, Commodore released several niche hardware enhancements for sound manipulation. These included the "Sound Expander", "Sound Sampler", "Music Maker" overlay, and External music keyboard. The Sound Expander and Sound Sampler were both expansion cartridges, but had limited use. The Sound Sampler in particular could only record close to two seconds of audio, rendering it largely useless. The Music Maker was a plastic overlay for the Commodore 64 "breadbox" keyboard, which included plastic piano keys corresponding to keys on the keyboard. The External keyboard was an add-on that plugged into the Sound Expander. These hardware devices did not sell well, perhaps due to their cost, lack of adequate software, marketing as home consumer devices, and a result that turned many serious musicians off. Possibly the most complex C64 peripheral was the Mimic Systems Spartan, which added an entire new computer architecture to the C64, with its own 6502 CPU and expansion bus, for software and hardware compatibility with the
Apple II. Announced shortly after the Commodore 64 itself at a time when little software was available for the machine, the Spartan did not begin shipping until 1986, by which time the C64 had acquired an extensive software library of its own. Essentially an
Apple II+ compatible computer that used the 64's keyboard, video output, joysticks, and cassette recorder, the Spartan included 64kB RAM, a motherboard with a 6502 CPU on a card, 8 Apple-compatible expansion slots, an Apple-compatible disk controller card, and a DOS board to add to your 1541 disk drive. The DOS board was optional, but if it was not installed an Apple
Disk II or compatible drive would be required to load software. The long delay between announcement and availability, along with heavy promotion including full-page ads running monthly in the Commodore press, made the Spartan an infamous example of
vaporware. Gamesware produced a
gaming peripheral for the Commodore 64 in 1988, where a target board was attached to the computer using the RS-232 port to enable use of its
Gamma Strike suite of games.
CMD produced a
SID symphony cartridge later in the Commodore's life. A reworking of the original Dr. T's SID Symphony cartridge, this cartridge gave the Commodore another SID chip for use to play stereo SID music. This saved Commodore 64 users from needing to modify their computer motherboards to enable it with dual SID chips.
Creative Micro Designs (CMD) was the longest-running third-party hardware vendor for the Commodore 64 and
Commodore 128, hailed by some enthusiasts as being better at supporting the Commodore 64 than Commodore themselves. Their first commercial product for the C64 was a
KERNAL based fast loader and utility chip called JiffyDOS. It was not the first KERNAL-based enhancement for the C64 (SpeedDOS and DolphinDOS also existed), but was perhaps the best implemented. The benefits of a KERNAL upgrade meant that the cartridge port was free for use (which would have normally been taken up by an
Epyx FastLoad cartridge or an
Action Replay), however the downside meant that one had to manually remove
computer chips from the C64's
motherboard and associated floppy drives to install it. Aside from the usual 1541 fast load routines, JiffyDOS contained an easy-to-use
DOS and a few other useful utilities.
RAM expansions Over the years, a number of RAM expansion cartridges were developed for the Commodore 64 and 128. Commodore officially produced several models of
RAM expansion cartridges, referred to collectively as the 17xx-series
Commodore REUs. While these devices came in 128, 256, or 512
kB sizes, third-party modifications were quickly developed that could extend these devices to 2
MB, although some such modifications could be unstable. Some companies also offered services to professionally upgrade these devices. Typically, most Commodore 64 users did not require a RAM expansion. Very little of the available software was programmed to make use of expansion memory. The cost of the units (and the requirement to add a heavy-duty power supply) also was a factor in the limited usage of RAM expansion cartridges. The volatility of DRAM was also a factor in the limited usage, as the RAM expansion cartridges were normally used for fast
RAM disk storage, data stored on them would be lost at any power failure. Aside from power supply problems, the other main downfall of the RAM expansions were their limited usability due to their technical implementation. The RAM in the expansion cartridges was only accessible via a handful of hardware registers, rather than being CPU-addressable memory. This meant that users could not access this RAM without complicated programming techniques. Furthermore, simply adding the RAM expansion did not provide any kind of on-board RAM disk functionality (though a utility disk was supplied with some REUs, which provided a loadable RAM disk driver). One popular exception to the disuse of the REUs was
GEOS. As GEOS made heavy use of a primitive, software-controlled form of
swap space, it tended to be slow when used exclusively with floppy disks or hard drives. With the addition of an REU, along with a small software driver, GEOS would use the expanded memory in place of its usual swap space, increasing GEOS' operating speed. Due to the lack of available 17xx-series Commodore REUs, and then their later discontinuation,
Berkeley Softworks, the publishers of GEOS, developed their own 512 kB RAM expansion cartridge, the GeoRAM. This device was purposely designed for use with GEOS, although some REU-aware programs were later adapted to be able to use it. Some time later, the GeoRAM was cloned by another company to form the BBGRAM device (which also sported a battery backup unit). The GeoRAM used a banked-memory design where portions of the external
DRAM were banked into the Commodore 64's CPU address space. This method provided substantially slower transfer speeds than the single-cycle-per-byte transfer speeds of the Commodore REUs. The GeoRAM utilized four 1 Mbit-density DRAM chips arranged as two banks of two 256Kx4 DRAM ICs. A benefit of using denser DRAM was lower power consumption, and so the GeoRAM did not require upgrading the Commodore 64's power supply, in contrast with the 17xx-series REU memory expansion cartridges. Eventually the
Super 1750 Clone, a third-party clone of Commodore's RAM expansions was developed, designed in such a way as to eliminate the need for a heavy-duty power supply. PPI devised their own externally powered 1 or 2 MB RAM expansion, marketed as the PPI/CMD RAMDrive, which was explicitly designed to be used as a RAM disk. Its primary feature was that the external power supply kept the formatting and contents of the RAM safe and valid while the computer was turned off, in addition to powering the device in any case. A driver was provided on the included utilities disk to allow GEOS to use the RAMdrive as a regular 'disk' drive. CMD later followed up with the
RAMLink. This device operated similar to the RAMDrive, but could address up to 16 MB of RAM in the form of a 17xx-series REU, GeoRAM, and/or an internal memory card, which also provided a battery-backed
realtime clock for file time/date stamping of files saved to it. It also features a battery backup, thus preserving the RAM's contents. Drivers were provided with the RAMLink to allow GEOS to use its memory as either a replacement for swap space, or as a regular 'disk' drive. CMD's
Super CPU Accelerator came after this and could house up to of direct, CPU-addressable RAM. Unfortunately, there was no on-board or disk-based RAM disk functionality offered, nor could any existing software make use of the directly addressable nature of the RAM. The exception is that drivers were included with the unit to explicitly allow GEOS to use that RAM as a replacement for swap space, or as a regular 'disk' drive, as well as to make use of the acceleration offered by the unit.
EPROM programmers burner for C64 user port Programmers for
EPROMs like 2716 - 27256 using common programming voltages (Vpp) of 12.5, 21, and 25 V were available by connecting a device to the user port of the C64. These devices could cost in 1985. The device often included a
zero insertion force (ZIF) socket and a LED indicating when the EPROM chip was being programmed. The cartridge port was also used by some programmer devices.
Freezer, Reset, and Utility cartridges Probably the most well-known
hacker and development tools for the Commodore 64 included "Reset" and "Freezer" cartridges. As the C64 had no built-in
soft reset switch, reset cartridges were popular for entering game "
POKEs" (codes which changed parts of a game's code in order to cheat) from popular Commodore computer magazines. Freezer cartridges had the capability to not only manually reset the machine, but also to dump the contents of the computer's memory and send the output to disk or tape. In addition, these cartridges had tools for editing game
sprites,
machine language monitors, floppy fast loaders, and other development tools. Freezer cartridges were not without controversy however. Despite containing many powerful tools for the programmer, they were also accused of aiding unauthorized distributors to defeat software copy protections. Perhaps the best-known freezer cartridges were the
Datel "
Action Replay",
Evesham Micros Freeze Frame MK III B, Trilogic "Expert", "
The Final Cartridge III", Super Snapshot and
ISEPIC cartridges. The
Lt. Kernal hard drive subsystem included a push button on the
host adapter called ICQUB (pronounced "ice cube"), which could be used to halt a running program and capture a
RAM image to disk. This would work with most copy-protected software that did not do
disk overlays and/or bypass the
KERNAL ROM
jump table. The RAM image was runnable only on the Lt. Kernal system on which it was captured, thus preventing the process from being used to distribute unlicensed software.
Music and Synthesizer utilities As the Commodore 64 featured a digitally controlled semi-
analogue synthesizer as its sound processor, it was not surprising to discover an abundance of software and hardware designed to expand upon its capabilities. Various assemblers, notators,
sequencers,
MIDI editing and mixer automation software were created which allowed users and programmers to create or record musical pieces of impressive technical complexity. Some software of note has included the
Kawasaki Synthesizer range, Music System notation and MIDI suite, the MIDI-compatible Instant Music 'idiot-proof' sequential composer, and the Steinberg Pro-16 MIDI sequencer, the precursor to
Cubase. Notable hardware included various brands of MIDI cartridges, plug-in keyboards (such as the or the Commodore's own SFX range which included a sound sampler and plug-in synthesizer and keyboard, the more recent Commodulator oscillator wheel and the sequencer and synthesizer utility cartridge. The Passport Designs MIDI Interface is said to be one of the best designs and had the most software supported model available. It came with the "DOS Card" addition, an Apple II disk controller that was installed inside the
Commodore 1541 disk drive, between the floppy logic board and the drive mechanism. In normal mode the circuit simply passed signals through but at the flick of a switch it could take over the mechanism and turn the drive into an Apple II drive. The potential for grave damage to both Apple II and 1541 floppies was enormous and often happened. The box had to configure.
Applesoft BASIC was included and very compatible, since it was created by
disassembling the binary from the Applesoft ROM and reordering the assembly level instructions such that the binary image would be different. One could set up various debugging and use
slave computing to enable fast 3D rendering etc. The box had functionality to switch video between C64 and Apple. The second advertisement was put into the ''
COMPUTE!'s Gazette'' in 1986.
CP/M with Z80 CPU cartridge The Commodore C64
CP/M Cartridge uses the
C1541 floppy drive which was incapable of reading any existing CP/M disk format. The cartridge were equipped with a
Zilog Z80 CPU running at around
CPU accelerators Like the
Apple II, third-party acceleration units providing a faster CPU appeared late in the C64's life. Due to timing issues with the
VIC-II video controller, CPU accelerators for the 64 were complex and expensive to implement. So while accelerators based upon the
Western Design Center (WDC)
65C02—usually running at 4 MHz, and the WDC
65C816 16-bit microprocessor running at 4, 8 or 20 MHz, were produced, they appeared too late and were too expensive to gain widespread use. The first CPU accelerator seen was called the "Turbo Process" by a
Bonn, Germany, based company called Roßmöller GmbH. It used the WDC 65C816 microprocessor running at 4.09 MHz. Code ran from faster
static RAM on the accelerator expansion port cartridge. As the VIC video controller can only access the C-64's internal DRAM, writes had to be mirrored to the internal memory; write cycles would slow the operation of the processor to accomplish this. The
Turbo Master CPU, produced by US-based Schnedler Systems, was a hardware clone of the Roßmöller Turbo Process product with minor logic changes and a blue aluminum case. It was an expansion port device clocked at 4.09 MHz. It also had a JiffyDOS option. Early Turbo Process circuit boards shipped with
PAL chips that did not have their security fuses blown, an oversight which made duplicating the PAL logic and hence the cartridge design trivial. No known litigation took place over the copying of the German company's design. The Turbo Master CPU had one beneficial modification, the bit to toggle the high-speed mode on was "0" in memory location $00 as opposed to the "1" the Turbo Process. A lot of software would write zeros to this location turning off the high-speed mode on the Turbo Process - this was considered a design flaw that was fixed by the Turbo Master. The most well-known accelerator for the C64 is probably
Creative Micro Designs'
SuperCPU, which was equipped with the WDC W65C816S (the
static core version of the 65C816) clocked at 20 MHz, and with up to 16 MB of RAM if combined with CMD's
SuperRamCard. Understandably, due to a very limited "market" and number of developers, there has not been much software tailored for the SuperCPU to date — however
GEOS was supported. Among the few offerings available are the Wheels; a Wheels-based web browser called "The Wave", a
Unix/
QNX-like graphical OS called Wings, some demos, various classic games modified for use with the SuperCPU, and a shooter game in the old
Katakis-style called
Metal Dust.
Present and Future devices While CMD no longer produces Commodore hardware, new peripherals are still being developed and produced, mostly for mass storage or networking purposes. The MMC64 cartridge allows the C64 to access
MMC- and
SD flash memory cards. And several revisions and add-ons have been developed for it to take advantage of extra features. It features an Amiga
clock port for connecting a RR-Net Ethernet-Interface, an
MP3 player add-on called 'mp3@c64' has even been produced for it. In February 2008, Individual Computers started shipping the MMC Replay. It unites the MMC64 and the Retro Replay in one cartridge, finally built with proper case-fit in mind (even including the RRnet2 Ethernet add-on). It contains many improvements, such as C128 compatibility, a built-in .d64 mounter (not speedloader-compatible though, because the 1541 CPU is not emulated), ROM for a total of eight cartridges, 512 kB RAM, a built-in flash-tool for cartridge images and wider support for various types of cartridges (not merely Action-replay-based). In April 2008, the first batch of
1541 Ultimate shipped, a project by the hobbyist
VHDL-developer Gideon Zweijtzer. This is a cartridge that carries an Action Replay and Final Cartridge (whatever the user prefers) and a very compatible
FPGA-emulated 1541 drive that is fed from a built-in SD-card slot (.d64, prg etc.). The difference to other SD-based and .d64 mounting cartridges like the MMC64, Super Snapshot 2007 or MMC Replay is, that the
6502 that powers the 1541 Floppy and the 1541's mechanical behavior (even sound) is fully emulated, making it theoretically compatible with almost anything. File selection and management is done via a third button on the cartridge that brings up a new menu on screen. The 1541 Ultimate also works in standalone mode without a c-64, functioning just like a normal
Commodore 1541 would. Disk-selection of .d64s is then done via buttons on the cartridge, power is supplied via USB. There is a "Plus-Version" available with an extra 32 Megabytes of RAM (as REU and for future use), the basic version has just enough RAM for the advertised functions to work. In October 2008, the second and third batch of 1541 Ultimates were produced to match the public demand for the device. The regular version without the 32MB RAM was dropped since there was no demand for it. Due to public demand, there is also a version with Ethernet now. In 2010 a completely new PCB and software has been developed by Gideon Zweijtzer to facilitate the new 1541-Ultimate-II cartridge. The
IDE64 interface cartridge provides access to
parallel ATA drives like hard disks,
CD/
DVD drives,
LS-120,
Zip drives, and
CompactFlash cards. It also supports network drives (PCLink) to directly access a host system over various connection methods including X1541,
RS-232,
Ethernet and
USB. The operating system called
IDEDOS provides
CBM/
CMD compatible interface to programs on all devices. The main filesystem is called CFS, but there's read-only support for
ISO 9660 and
FAT12/16/32. Additional features include
BASIC extension,
DOS Wedge,
file manager,
machine code monitor,
fast loader,
BIOS setup screen. Today's computer mice can be attached via the Micromys interface that can process even optical mice and similar. There are also various interfaces for plugging the 64 to a PC keyboard. A board for converting Commodore 64 video signals to standard
VGA monitor output is also currently under development. Also, a board to convert the Commodore 128's 80 column RGBI
CGA-compatible video signal to VGA format was developed in late 2011. The board, named the C128 Video DAC, had a limited production run and was used in conjunction with the more widespread GBS-8220 board. In September 2008, Individual Computers announced the Chameleon, a Cartridge for the Expansion Port that adds a lot of previously unseen functionality. It has a Retro-Replay compatible Freezer and MMC/SD-Slot, REU and a
PS/2 connector for a PC Keyboard. Support for a network adapter and battery-backed real time clock exists. The cartridge does not even have to be plugged into a Commodore 64 and can be used as a standalone device using USB power. Since the cartridge essentially also includes a Commodore One it is possible to include a
VGA Port that outputs the picture to a standard PC monitor. The Commodore One core also allows the cartridge to be used as a CPU accelerator, and a core to run a
Amiga environment in standalone mode also exists. Unlike most other modern-day C64 hardware, this cartridge ships with a bright yellow case. Shipping was announced for Q1/2009, and currently the cartridge is available, although the firmware is in a beta state. A standalone mode docking station is under development. Retro Innovations is shipping the
uIEC device, which utilizes the core design of the
SD2IEC project to provide a mass media solution for Commodore 8-bit systems that utilize the Commodore IEC Serial Bus. NKCElectronics of Florida is shipping SD2IEC hardware which uses the sd2iec firmware. Manosoft sells the C64SD Infinity, another
SD card media solution which uses the sd2iec firmware. In Summer of 2013, another commercial variant of the SD2IEC-Device appears on market, the SD2IEC-evo2 from 16xEight. This device uses a bigger uC (ATmega1284P) and includes extras such as battery-backed RTC, connector for LCD, and multicolour status LED. 2014 sees the emergence of another commercial variant of SD2IEC hardware. thefuturewas8bit SD2IEC Versions are available packaged to resemble a miniature 1541 disk drive. It has illuminated disk change and reset buttons accessible from the top of the case. == Notes ==